Technique-specific high-intensity interval training (HIIT_TS) has been proven to be an effective method to enhance the sport-specific bio-motor abilities of taekwondo athletes. However, studies regarding its effects on comprehensive measures of cardiorespiratory fitness are limited. Furthermore, there is a lack of clarity regarding the extent of individual adaptations to this method compared to HIIT in the form of repeated sprints (HIIT_RS). This study compared the individual adaptations to HIIT_RS and HIIT_TS on cardiorespiratory fitness and anaerobic power in trained taekwondo athletes (age = 19.8 ± 1.3 years; body mass = 75.4 ± 9.1 kg; height = 1.73 ± 0.0 .m). All participants completed three sessions per week of a 60-minute regular taekwondo training. Following the 60-minute training, participants completed 3 sets of 10 × 4 s all-out HIIT_RS or same sets of repeated kicks with both legs (HIIT_TS) over a 6-week training period. In both groups, rest intervals were set at 15 seconds between efforts and one minute between sets. Before and after the training period, participants underwent a series of lab- and field-based tests to evaluate cardiorespiratory fitness and bio-motor abilities. Both interventions resulted in significant improvements in maximum oxygen uptake (V̇O_2max), O₂ pulse (V̇O₂/HR), first ventilatory threshold (VT₁), second ventilatory threshold (VT₂), cardiac output (Q̇_max), stroke volume (SV), peak power output (PPO), average power output (APO), squat jump (SJ), and countermovement jump (CMJ). However, linear speed (20-m speed time) and taekwondo-specific agility test (TSAT) only responded to HIIT_RS. HIIT_RS resulted in greater changes in V̇O_2max, V̇O₂/HR, VT₂, and Q̇_max, and higher percentage of responders in measured parameters than HIIT_TS. In addition, HIIT_RS elicited lower inter-individual variability (CV) in percent changes from pre- to post-training in all measured variables. These results suggest that incorporating 3 sessions per week of HIIT_RS into regular taekwondo training results in significantly greater and more homogenized adaptations in cardiorespiratory fitness and bio-motor abilities than HIIT_TS among trained taekwondo athletes.

• High-intensity technique-specific interval intervention sufficiently stimulates adaptive mechanisms responsible for enhancing aerobic and anaerobic power in taekwondo athletes.

• However, engaging in HIITRS leads to significantly greater improvements in cardiorespiratory fitness compared to technique-specific HIIT.

• HIITRS results in more consistent adaptations than HIITTS across individuals.